Freeze

Freeze is an effect in the Object subcategory, which will freeze a unit that's referenced by an Object. A frozen unit cannot move, cannot be controlled by anyone, cannot be damaged, and will have a red X if you place your mouse over it.

An interesting note, ground units and helicopters will stop and not move, however, airplanes will circle around, and not use flight time (fuel)

The effect Unfreeze will remove this effect.